DPD 118-1000 MHz LP antenna first impressions

[mancow]

Draw no conclusions from anything you hear on 29.620. Those repeaters are hearing things rom several States and even Countries at a time. Maybe your local PD issues are due to overload from nearby transmitters that are swamping the receiver with the added performance of the new antenna.

 

[EricCottrell]

Hello,

I ordered the antenna today. I will use a rotator as it will replace a couple of small beams I am using (220 and 440 MHz). I understand about insulating the boom.

Antenna position and direction seems more critical at 800. I used some 800 MHz yagis while portable and sometimes the best signal is not in the same direction that you think is the best direction.

73 Eric

 

[radiopro52]

It's the kind of thing that just takes a little practice, but it's not hard. I know there's a lot of people that have the same issues with cable. I've thought for a long time on how I could help, but I haven't come up with anything. The problem is that, until you start buying thousands of feet of cable, the cable makers will barely give you any price break at all. Unless you buy huge amounts, they prefer you at least go through a distributor. Lots of times I can't even do that. So then it's like I'm almost paying as much as everybody else. It's not like the old days where anybody with a business gets a wholesale price. It's very similar with connectors as well. So even on the expensive stuff, I'd be lucky to get .10 profit a foot. On top of that, I know that no matter what cable I carried, people would always want something else. So now you're looking at having thousands of dollars of cable laying around, just so you can help the occasional person who needs something. It's just tough spending that kind of money these days to inventory something that has so low a profit margin. You'll see the same reflected in what few electronic supply places are left. Most don't stock half of what they did just 10 years ago. Even in a city as big as L.A., you're hard pressed just to find many connectors. The internet is great, but it's also had a very negative effect in that regard.

Dave
http://www.dpdproductions.com
Antennas & Accessories for the RF Professional & Radio Hobbyist

I've looked on thewireman.com and they carry a wide variety of coax, even the harder to find LMR500 and up (but not worth the extra cost, imo). But by the time you add up the cost of the coax alone, and then add the extra cost of the connectors, you're looking at quite a price just to get an N connector. And as for ripping off the PL-259 connector and installing an N connector, I'd be for it, but I don't know what I'm doing when it comes to that and I don't know of anyone around here that offers such service.

And you're totally correct on the pricing and profit. It's tough out there. I've seen sellers on Ebay and elsewhere selling thousands of feet of coax, and I'm wondering "Who would need a cable that long"? But I guess some do if they're professional radio operators or operate radio stations. I myself have been buying more online than in stores.

 

[blantonl]

Interesting question. The Fort Worth, Texas public safety trunk system has always done that to me. Not just on every scanner, but on Motorola radios too. It's a weird, hollow, throaty sounding scratchiness that gets better with signal strength, but never totally goes away, even in the middle of town. I haven't figured it out.

It is multipath simulcast problems... I recall living in the DFW area and this being more pronounced when monitoring FW outside of Tarrant County.

They might have a GPS unit or faulty timing system implemented on the system....

 

[DPD1]

I've looked on thewireman.com and they carry a wide variety of coax, even the harder to find LMR500 and up (but not worth the extra cost, imo). But by the time you add up the cost of the coax alone, and then add the extra cost of the connectors, you're looking at quite a price just to get an N connector. And as for ripping off the PL-259 connector and installing an N connector, I'd be for it, but I don't know what I'm doing when it comes to that and I don't know of anyone around here that offers such service.

Yeah, that's another problem... Nobody knows how to do anything anymore. It's very hard to find anybody that can do technical stuff. But yes, it would be silly to buy a whole new cable for a connector. I'd do it for you, but you're just a bit of a drive. The clamp ones are pretty easy because you don't need a special crimper or anything. The only special thing you need is a soldering iron. It's just a matter of stripping back each thing the right length, then you solder the pin on and screw the top shut. Getting the right amount stripped back is the tricky part, but you can always just cut the end and start over. I can tell you how to do it exactly if you want to try it sometime.

Dave
www.DPDProductions.com
Antennas & Accessories for the RF Professional & Radio Hobbyist

 

[radiopro52]

Yeah, that's another problem... Nobody knows how to do anything anymore. It's very hard to find anybody that can do technical stuff. But yes, it would be silly to buy a whole new cable for a connector. I'd do it for you, but you're just a bit of a drive. The clamp ones are pretty easy because you don't need a special crimper or anything. The only special thing you need is a soldering iron. It's just a matter of stripping back each thing the right length, then you solder the pin on and screw the top shut. Getting the right amount stripped back is the tricky part, but you can always just cut the end and start over. I can tell you how to do it exactly if you want to try it sometime.

Dave
www.DPDProductions.com
Antennas & Accessories for the RF Professional & Radio Hobbyist

Come on. 2,000 miles isn't that bad. Just kidding.

I don't even know how the connector is on the coax; if it's clamp or another type. I bought the coax from theantennafarm.com, but he also has a store on Ebay so I bought it from there. The connectors seem to be good quality. The PL-259 connector is goldish in color and has a black seal. I wouldn't even know how to safely pull the thing off without damaging anything. But thanks for the offer, and I'll definetley consider it.

Here's a picture of the connector, connected to the adapter which is connected to the RG58 from the antenna. I got as close of a shot as I could get. You can also see the stand-off in the photo.

 

[mrdinks]

I have been looking at this antenna for months and finally sent my order. Keep us posted on the changes and what helps your reception.

 

[mancow]

I got mine installed today at around 23 feet.

It's EXCELLENT! I really, really like this thing. It's just as they describe on the site. There's good all around omni coverage with good gain to the front. Another thing that surprised me is the good high frequency response. I'm sitting here with two radios tuned to a very distant 800 Mhz system. One is on the DPD the other is on the RFS 1610-1 4 dbd gain omni. the omni is about four or five feet lower than the DPD but they are both performing the same. That really shocked me. I was expecting the commercial antenna to really outshine the DPD even though its a bit lower in elevation.

So far, Vhf and Uhf have been outstanding too. It's nice to have good performance across ALL the bands. Usually you find a spot where things kind of degrade but so far all ranges seem to be equally good.

I was really impressed with the buld quality. I didn't realize it has solid elements. That's a nice feature. It just feels like you actually have something of quality when you get it together instead of the POP can aluminum you get with other stuff.

Save your money people, lose the scantenna and get one of these!


I think I'm going to get one of the little Uhf / 800 Mhz models now.

 

[radiopro52]

I got mine installed today at around 23 feet.

It's EXCELLENT! I really, really like this thing. It's just as they describe on the site. There's good all around omni coverage with good gain to the front. Another thing that surprised me is the good high frequency response. I'm sitting here with two radios tuned to a very distant 800 Mhz system. One is on the DPD the other is on the RFS 1610-1 4 dbd gain omni. the omni is about four or five feet lower than the DPD but they are both performing the same. That really shocked me. I was expecting the commercial antenna to really outshine the DPD even though its a bit lower in elevation.

So far, Vhf and Uhf have been outstanding too. It's nice to have good performance across ALL the bands. Usually you find a spot where things kind of degrade but so far all ranges seem to be equally good.

I was really impressed with the buld quality. I didn't realize it has solid elements. That's a nice feature. It just feels like you actually have something of quality when you get it together instead of the POP can aluminum you get with other stuff.

Save your money people, lose the scantenna and get one of these!


I think I'm going to get one of the little Uhf / 800 Mhz models now.

Glad you are getting positive results. When you say a distant 800 Mhz system, how far away exactly?

I've noticed more intermod on my scanner lately. You been getting this too? Perhaps the BCT15 is too sensitive.

 

[ka3jjz]

Not 'too sensitive'; in reality it has more to do with the front end design, and how well it handles/doesn't handle strong signal levels. Consumer grade scanners simply can't always keep up. Some PAR filters in the line will knock down the interference. Expensive but well worth it.

Many people make the mistake of thinking bigger is better. Not always true.

73 Mike

 

[radiopro52]

Not 'too sensitive'; in reality it has more to do with the front end design, and how well it handles/doesn't handle strong signal levels. Consumer grade scanners simply can't always keep up. Some PAR filters in the line will knock down the interference. Expensive but well worth it.

Many people make the mistake of thinking bigger is better. Not always true.

73 Mike

The BCT15 is a great scanner though. I've heard nothing but good things about it. That's why I bought it, but I guess no scanner is perfect. Would a more expensive scanner, like the BC996T, have less intermod issues?

 

[ka3jjz]

This is a question that's almost impossible to answer - every area is different. If you were out in rural areas, for example, you might not notice this as much. But it could still occur. Nothing to prevent it.

My suspicion would be no, since I believe the basic circuit design for the 996 is quite similar to the 15. And although I don't have any experience to back up the guess, I would think the PSR 500 and 600 would also have overload issues of one kind or another. 73 Mike

 

[mrdinks]

Back to the topic..... I got my antenna today and mancow said it all. It is very well built, I can not say enough about the quality. Can not wait to get it up.

 

[mancow]

The system I am monitoring is right about 55 miles line of sight. It's Kansas City, MO and the terrain is fairly flat.

I was wrong in my initial description. The 800 Mhz gain omni is the same height as the DPD. I thought it was lower but I realized that it's not today when I looked at it again.

The DPD is pulling in KC, MO at the exact same level as the professional grade 4 dbd omni at the same level.


I was impressed.


As for intermod, I haven't had any issues yet.

Glad you are getting positive results. When you say a distant 800 Mhz system, how far away exactly?

I've noticed more intermod on my scanner lately. You been getting this too? Perhaps the BCT15 is too sensitive.

 

[radiopro52]

This is a question that's almost impossible to answer - every area is different. If you were out in rural areas, for example, you might not notice this as much. But it could still occur. Nothing to prevent it.

My suspicion would be no, since I believe the basic circuit design for the 996 is quite similar to the 15. And although I don't have any experience to back up the guess, I would think the PSR 500 and 600 would also have overload issues of one kind or another. 73 Mike

Well, I do kinda live in a rural area. There are two small cities about 10 miles from me, and the nearest big city is about 30 miles away. So, I don't live in a very urban area. Still, i guess there are many stations within a 50 mile radius or so that share the same frequencies that I listen to.

And mancow, 55 miles on a 800 Mhz system? Very impressive. I know you got your money's worth out of it. And it seems the longer you have the antenna, the better it performs.

 

[EricCottrell]

Hello,

I installed the antenna this morning. Good build quality. I replaced 220 MHz and 440 MHz beams. I only got to do a quick test because work got in the way.

I get slightly less signal from a UHF site about 60 Miles away compared to the UHF Beam. I expect that since yagi beams do better. However I can also hear a UHF site with about a 50 percent quieting signal that is over 90 Miles away. I could not hear the 90 Mile site with the UHF Beam unless there was lift. There may be some lift this morning because the signal levels where up and down. The new LPA antenna is not at the same height as the old 440 MHz beam was so that can affect signals.

I was able to pick up MA State Police Zone 6 from Truro on the Cape pretty good. This is about 58 miles with a mostly over water path. I can also hear the Worchester EDACS system but the control channel is not full quieting. Nashua NH is full quieting. With the discone I can only get Nashua with a weaker signal.

I want to try some NH State Police stuff this evening. So far the antenna is working well.

73 Eric

 

[radiopro52]

That's great Eric. I think I've heard nothing but good about DPD's antennas. No matter what antenna you are currently using, you should notice an increase in performance with a DPD.

With some band opening (ducting) going on, the LP really pulls in signals. I was picking up a weak radio station out of state last night, as well as several ham repeaters out of state. With the ducting, the LP actually gets better omni-directional performance than the 20-176.

 

[EricCottrell]

That's great Eric. I think I've heard nothing but good about DPD's antennas. No matter what antenna you are currently using, you should notice an increase in performance with a DPD.

With some band opening (ducting) going on, the LP really pulls in signals. I was picking up a weak radio station out of state last night, as well as several ham repeaters out of state. With the ducting, the LP actually gets better omni-directional performance than the 20-176.

Hello,

Yeah the over 90 Mile signal was a slight band opening.

I was getting good results listening to the Salem NH police and NH SP in Southern NH. They had fair signals with the discone but have a nicer signal margin on the LPA. I have hills to the north so NH stuff is not as good as towards Cranston, RI.

I am planning to redo my antennas in a few weeks and may put the beam higher.

73 Eric